Was reading up in stella/solar system formantion LINK , and was wondering what stops the whole mass of the collapsing cloud from forming just one "object"

Is it just a matter of how much mass the central body (Star?) can put on before the thermonuclear fires stop anymore mass accreation?

and whats the go with "jets" and "doughnuts" and "butterfly" shapes in things like black holes, Neutron,pulsar,quasars, active galaxys and high mass stars, could there maybe some connection or something.

I understood it to be that the cloud collapses forming a central star and the "left overs" form the rest of the stuff (planets,moons & comets etc etc) but if the radiation pressure from the central star firing up, wouldn't that stop the "rest" of the stuff forming?